This invention deals primarily with an apparatus used to form, shape, and compact ground meat into a square-shaped block preferably having a plurality of perforations longitudinally extending through the block of ground meat. More particularly, the invention relates to an apparatus of the foregoing type which is attached to a meat grinder or the like to continuously form a block of meat that can be cut into patties including ones having a pattern of perforations.
The use of pre-formed, frozen meat patties in the food industry has long been recognized as a fast and easy method for the preparation of fast-food hamburgers. The process generally begins with the grinding of frozen or semi-frozen meat. It has been long recognized that meat at low temperature could be easily shaped and still be sufficiently cold to prevent bacterial growth particularly when the ground meat is forced by the action of the meat grinder into an apparatus attached to the output nozzle of a meat grinder. Such an apparatus acts as an extruder with continuously decreasing diameters through which the ground meat is forced, thereby shaping and compacting the ground meat.
In addition, it has been known that provision of perforations in the meat patties expedited the time required for cooking and enhanced the flavor of the meat. With the extrusion nozzle type of patty forming these perforations were produced through the insertion of a desired pattern of solid rods into the extrusion apparatus and the meat was compressed around these rods, thereby producing perforations in the solid block of meat as it exits the extruder. When the block is then cut into patties each will have the pattern of perforations determined by the number and disposition of the nozzle rods.
This method of the extrusion of ground meat is generally illustrated in U.S. Pat. No. 2,670,296, now expired. The design there shown, however, was recognized to have had certain flaws which enhanced the tendency for the meat to freeze up in the mechanism and provided certain internal surfaces which were difficult to clean.
The above mentioned U.S. Pat. No. 2,670,296 for the preparation of meat patties was subsequently improved as shown and described in U.S. Pat. No. 3,512,213 wherein an extrusion nozzle was provided with detachable nozzle sections for dealing with cleaning aspects, but which still required an electrically energized heating device to provide warmth in order to prevent freezing within the mechanism. The internal rods were securely mounted on a core device located well within the sectional extruder nozzle and the rod ends extended outwardly past the end of the apparatus.
The multi-sectional, detachable nature of this extruder nozzle is also believed to have required supplemental heating to prevent freeze ups and offered a significant number of areas at sectional interfaces and around the detachable frame which would still be difficult to clean and can impede the smooth flow of meat through the extruder nozzle.